Save migration directory

Dockerfile

@@ -6,4 +6,6 @@ WORKDIR /app
 RUN bundle install
 ENV ENV developpement
 ENV IP 0.0.0.0
+VOLUME /app/db
+RUN cp -r /app/db/migrate /migrations
 ENTRYPOINT /app/entrypoint.sh

entrypoint.sh

 #!/bin/bash
-./bin/rails db:migrate
+mkdir -p /migrations/* /app/db/migrate/
+cp -r /migrations/* /app/db/migrate/
+RAILS_ENV=$ENV ./bin/rails db:migrate
 ./bin/rails server -e $ENV -b $IP